What is that little voice inside my head? Inner speech phenomenology, its role in cognitive performance, and its relation to self-monitoring.

Precise neural differences between inner and produced speech remain elusive.

“Precise neural differences between inner and produced speech remain elusive25,32,47,48.”

Inner speech is implicated in silent reading, with many people reporting evoked auditory or motor speech imagery while reading.

“It is also implicated in silent reading, with many people reporting evoked auditory or motor speech imagery while reading32,33.”

We sometimes deliberately engage in inner speech, called willful or intentional inner speech, and other times unintentionally use inner language, called verbal mind wandering or spontaneously occurring inner speech.

“We sometimes deliberately engage in inner speech (when we rehearse material in short-term memory), what can be called willful or intentional inner speech. Other times, we find ourselves unintentionally using inner language, what has been called verbal mind wandering (Perrone-Bertolotti et al., 2014) or spontaneously occurring inner speech (Hurlburt et al., 2016).”

In the preliminary account, inner speech monitoring was based on a predictive control scheme inspired from Frith et al. (2000) and described in Rapin et al. (2013) and Perrone-Bertolotti et al. (2014).

“In this preliminary account, inner speech monitoring was based on a predictive control scheme, inspired from Frith et al. (2000) and also described in Rapin et al. (2013) and Perrone-Bertolotti et al. (2014).”

Inner speech can be associated with auditory as well as somatosensory representations.

“As we have argued in Lœvenbruck et al. (2018) and Perrone-Bertolotti et al. (2014), inner speech can be associated with auditory as well as somatosensory representations.”

Inner speech appears to be an important part of silent reading.

“Inner speech also appears to be an important part of silent reading (see Perrone-Bertolotti et al., 2014, for a recent review).”

Verbal mind-wandering may involve an abstract form of inner speech while voluntary verbal thought may have a more concrete form, and this distinction might map on to the anticorrelation between default mode network activation and task-positive activation of language networks.

“It has been suggested by Perrone-Bertolotti et al. (2014) that verbal mind-wandering may involve an abstract form of inner speech while voluntary verbal thought may have a more concrete form, and that this distinction might map on to the anticorrelation between default mode network activation and task-positive activation of language networks.”